Effects of Strength and Orientation of Steel Fiber on the Fracture Behavior of Steel Fiber Reinforced Concrete

钢纤维强度和取向对钢纤维混凝土断裂行为的影响

• 批准号: 03805062
• 负责人: SUTO Hajime
• 金额: $ 1.02万
• 依托单位: Tohoku Gakuin University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1991
• 资助国家: 日本
• 起止时间: 1991 至 1993
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-03805062/
• 关键词: fiber reinforced concrete; composite material; modulus of elasticity; bending strength; steel fiber; mortar; autoclave; 破断強さ; 鋼繊維強化コンクリート; 繊維強化モルタル; 曲げ強度; ガラス繊維; 複合則; コンクリ-ト; 鋼繊維強化コンクリ-ト; 繊維強化コンクリ-ト; ステンレス鋼; 曲げ試験

Various fiber reinforced concretes have been investigated. Their fibers have usually micro-meter order in diameter. Exceptionally, the diameter of steel fiber in SFRC is 0.1-1.0 mm. Therefore, the mechanical behaviors seems to be similar to those of RC.In this investigation, the effects of strength and orientation of steel fiber in mortar on the modulus of elasticity and facture strength of steel fiber reinforced mortar (SFRM) have been studied. The steel fiber used is "SHINKO-steel fiber", whose nominal dimensions are 0.6 mm in dia, 30 mm in length and more than 100 kgf/mm^2 in tensile strength. Various kinds of fibers having other sizes and strengths were also used. The size of specimen was 40X40X160 mm^3, and after aging for more than 28 days, tests were carried out. Results obtained are as follows : (1)Even 1 wt% addition, SF suppress the propergation of cracks. But the amount of SF contributing to strengthening is more than 5wt%. (2)The modulus of elasticity decreases by addition of SF, but by the mixing of optimum amount of expand cement, the decreasing can be controlled. (3)Greased SF dose not contribute to strengthening. (4)The role of SFs having 10 micr-meter in diameter or having 10mm in lengthare small. (5)The longitudinally oliented SF can contribute to strengthening effectively. (6)The modulus of elasticity decreased after autoclave-treatment at 180 ﾟC.

对各种纤维增强混凝土进行了研究。它们的纤维直径通常为微米级。特殊情况下，SFRC中钢纤维直径为0.1-1.0 mm。因此，其力学行为似乎与钢筋混凝土相似。本文研究了砂浆中钢纤维的强度和取向对钢纤维增强砂浆的弹性模量和断裂强度的影响。所使用的钢纤维为“shinko钢纤维”，其标称尺寸为直径0.6 mm，长度30 mm，抗拉强度大于100 kgf/mm^2。还使用了不同尺寸和强度的各种纤维。试件尺寸为40X40X160 mm^3，老化28 d以上后进行试验。结果表明：(1)即使添加量为1 wt%， SF也能抑制裂纹扩展。但SF对强化的贡献超过了5wt%。(2)顺丰粉的掺入使混凝土的弹性模量下降，但掺加适量膨胀水泥可使其弹性模量下降得到控制。(3)加脂后的SF无助于强化。(4)直径为10微米或长度为10毫米的sf的作用较小。(5)纵向定向的SF能有效促进强化。(6)在180°C高压灭菌后，弹性模量下降。